This article is a collaboration between MedPage Today® and:
AUSTIN, Texas -- In a small group of perinatal stroke patients, intentional cooling in the NICU was associated with a total lack of seizures and improved long-term language, cognitive, and neuromotor scores, researchers reported here.
The use of therapeutic hypothermia to treat focal stoke was associated with a lack of seizures in a small group of neonates (P<0.01), which may have been responsible for better language and cognitive scores at 12 months (mean 12 points, 95% CI minus 7-32, P=0.18) and 30 months (mean 31 points, 95% CI minus 9-71, P=0.1) of follow-up compared with babies not treated with hypothermia, according to Mary Jo Harbert, MD, of the University of California San Diego School of Medicine, and colleagues.
"People are often surprised to realize that stroke in newborns is as common as stroke in people over age 65. There is a disparity in neurology in that we don't have acute therapies for perinatal stroke whereas we have multiple ones for adult stroke," Harbert said at the Child Neurology Society's annual meeting.
In 2011 at the University of California San Francisco, Harbert and colleagues tested the use of therapeutic hypothermia to treat perinatal stroke. An assumption of HIE prompted the use of hypothermia. At that time, they discovered that hypothermia helped reduce the risk for seizures in the babies (P<0.01).
At this year's CNS meeting, the researchers presented evidence that the use of hypothermia was associated with improved long-term outcomes in the same group of neonates.
Based on MRI scans from 1994 to 2012, 14 out of 330 babies with encephalopathy were diagnosed with focal ischemic infarcts. Of the 14 stroke patients, five were treated with hypothermia. None of the babies treated with hypothermia had a seizure. Among the babies who were not treated with hypothermia, seven had seizures.
At 12 months after birth, 93% of the patients were assessed for cognitive and language progression with the Bayley Scales of Infant Development II or III, and neuromotor development. At 30 months after birth, 71% came in for another follow-up.
"At the 30-month mark, we were a little bit hampered by follow-up attrition," Harbert said.
At 12 months, the trend to improved cognitive and language scores was associated with hypothermia (mean 12 points, 95% CI minus 7-32, P=0.18). At 30 months, the trend to improved cognitive and language scores was associated with hypothermia (mean 31 points, 95% CI minus 9-71, P=0.1). The average score for the group of babies who did not receive hypothermia was 67 (standard deviation 18), compared with an average score of 98 in the cooled babies (SD 33).
At 12 months, none of the cooled babies had any abnormal neuromotor scores. On a scale from 0-6, with 0 being normal, the median interquartile range (IQR) for cooled babies was 0.0 (IQR=0.0). For babies who were not cooled, the median score was 2.0 (IQR=1.25).
By 12 months, there was a slight disparity between the groups (P=0.5), but by 30 months, the disparity between the groups had evened out (P=0.2).
In her presentation, Harbert noted that they were unsure if the hypothermia was associated with improved long-term outcomes because of a lack of neonatal seizures or because of some other underlying mechanism.
"Not all strokes are created equal, and it's possible that a variation in the degree of injury could have been responsible for this [better scores with hypothermia], so at the end of the day -- it's still a question of whether or not cooling is actually associated with improvement in outcomes in perinatal stroke. But given these findings it's a more compelling question than before," Harbert said.
"It also raises the interesting question -- is this [improvement] related to a lack of neonatal seizures? Cooling is regarded to be an anti-convulsant across the human age spectrum, but there has been no conclusive evidence to date that neonatal seizures by themselves are correlated with poor outcomes in neonatal stroke," Harbert continued.
Funding support was provided by the National Institutes of Health (NIH), the National Institute of Neurological Disorders and Stroke (NINDS), and the Cerebral Palsy International Research Foundation. Tam received support as a Ethel & Jack Hausman Clinical Research Scholar. The authors declared no conflicts of interest.
Child Neurology SocietySource Reference: Harbert MJ, et al "Therapeutic hypothermia is associated with improved outcomes in perinatal stroke" CNS 2013; Abstract PS2-3.